A DC-DC converter converts a direct current (DC) power source from one voltage level to another. A DC-DC converter may be, for example, a Buck DC-DC converter in which the input voltage is higher than the output voltage, a Boost DC-DC converter in which the input voltage is lower than the output voltage, or a Buck-Boost DC-DC converter in which the input voltage is higher or lower than the output voltage.
In a constant on-time voltage regulator, such as a Buck DC-DC converter, a Boost DC-DC converter, or a Buck-Boost DC-DC converter, a part of the output current of the DC-DC converter can be fed back to form a regulation loop. However, a propagation delay within the constant on-time voltage regulator can negatively impact the stability of the regulation loop of the constant on-time based DC-DC converter. For example, when the input voltage and the output voltage of the constant on-time voltage regulator are close to each other, the propagation delay within the constant on-time voltage regulator can cause sub-harmonic oscillation, which decreases the stability of the regulation loop of the constant on-time voltage regulator.